The present invention relates to improvements in a double-locking device for connector terminals and method of preparing the locking device.
Terminals in a connector are usuallly secured therewithin by means of struck-out pieces integrally formed in the terminals, with the struck-out pieces being engaged with the bottom wall of terminal holding chambers in an insulated housing. Alternatively, flexible engaging arms integrally formed from the ceiling of the holding chambers may be brought into engagement with shoulder portions or holes in electric contact portions of the terminals.
However, the struck-out pieces and engaging arms are so small in size that they are subject to damage as male and female connectors are attached and detached repetitively, thus resulting in frequent slip offs of the terminals or poor contact thereby.
Japanese Utility Model Publication No. 55-92284 discloses a connector as shown in FIG. 6 wherein a recess c is provided in a peripheral wall of the insulated housing a so as to communicate with terminal holding chambers b. Into the recess c is inserted a terminal fixing member f having projections each of which is complementary with the terminal holding chamber b in cross section and having a terminal retaining concave e at its lower end. The concave e holds and retains contact terminal d into which an electrical wire w is connected. The terminal fixing member f is fixed to the connector housing a by means of locking g, g', which consist of projections g' provided within the cavity c and on both side walls of the insulated housing a and openings g in the right and left end walls of the terminal fixing member f.
On the other hand, Japanese Utility Model Publication No. 54-28625 discloses a connector as shown in FIG. 7a and 7b wherein an insulated housing a' has a throughhole c' into which an insertion pin h is inserted so that it can be engaged at its side surface with a shoulder j or the like provided with an electrical contact portion i of contact terminal d'.
In the conventional connector as shown in FIGS. 6 and 7a and 7b, in addition to a locking means provided between the contact terminal and the corresponding terminal holding chamber, insertion members or spacers such as terminal fixing member f or insertion pin h as shown in the drawings are formed separately from the housing and contact terminal. However, after the terminals, are inserted, it often happens that the insertion of pins is inadvertently ommited. Furthermore, the number of parts of the connector increases, and laborious work is required for controlling the inventory.
It is therefore desired from the stand point of assembling operation and the control of inventory to provide a connector that can be handled as one piece part with insertion pins for double-locking of the terminals that is tentatively locked to the insulated housing, and that is capable of accomplishing main locking after the terminals are inserted.